Copper has long been the main material used to conduct electricity. Various copper alloys have been developed to overcome shortcomings of elemental copper, such as low strength and flexure life. High strength and flexure life, consistent with maintaining high conductivity, are important requirements for many applications.
While pure Cu and some copper alloys have good conductive performance (e.g. 100% IACS) these materials have low strength (e.g., 400 MPa) making them unsuitable for many applications. Strengthening Cu and its alloys can be achieved through several methods, such as grain refinement, precipitation hardening, cold working, or solid solution alloying. However, such approaches can lead to a decrease in conductivity. For example, alloying pure Cu by adding elements (Si, Al, Fe, Ni, Sn, Cd, Zn, Ag, Sb, Mg, Cr, etc.) may increase the strength by two or three times, but the electrical conductivity of Cu alloys can decrease dramatically. Furthermore, the volatilities of some alloy elements, such as Cd, Zn, Sn, and Pb, could limit their application in the electronics industry, especially in high temperature and high vacuum environments, Therefore, there is a need to develop copper alloys that have high strength and high conductivity.